Planetary transmissions are known transmission types for use in automotive vehicles. Due to their compact construction they enable a high performance density compared to other types of transmissions, a high torque transmission in a minimal design space as well as a variation of the translation ratio under load (i.e., without an interruption of force flow). At the same time, they also meet the requirements of a smallest possible structural and transmission weight.
The simplest form of a planetary transmission, a so-called one-step planetary transmission, basically comprises a sun gear, a number of planet gearwheels, and a planet gearwheel carrier as well as an annulus. The sun gear is in positive engagement with the internal-geared annulus through one or through each of the planet gearwheels used. Through the internal gearing of the annulus, these gearwheels can be arranged in a compact, space-saving arrangement. Depending on the required multiplication or reduction ratio, the planetary transmission can be configured with one or more planetary steps.
Basically, either the sun gear or the planet gearwheel carrier or the annulus can be driving, driven, or fixed members. In the ease of a sun gear driven by a driving shaft, the sun gear transmits, for instance, the torque through the annulus to the planet gearwheels mounted in the planet gearwheel carrier. Through the connection of the planet gearwheel carrier to a driven shaft, it becomes possible to achieve a multiplication or reduction of the transmission as a function of the number of teeth comprised in the respective gearwheel.
As a rule, the planet gearwheels are mounted on the planet carrier through bearing pins. The bearing pins thus function as rolling bearing raceways for the planet gearwheels.
For this reason, it is particularly important for the bearing pins to be mounted secure against rotation on the planet carrier or on an appropriate carrier element of a carrier arrangement in order to be able to guarantee a correspondingly disturbance-free functioning of the planetary transmission through the reliable positioning of the planet gearwheels. Normally, for this purpose, the bearing pins are staked on the planet carrier or on the carrier element so that a rotation and/or displacement of the bearing pin is prevented.
DE 10 2006 049 998 A1 discloses a planet gearwheel pin that is arranged in a carrier element of a planet gearwheel carrier configured as a guide disc. The planet gearwheel pin is connected to the guide disc by staking and comprises accordingly on its front end, at least one depression into which the material of the guide disc is staked.
A further arrangement of a planet pin in a planet carrier is disclosed in DE 10 2007 017 138 A1. The planet carrier comprises two so-called web metal sheets comprising reception apertures. Planet pins can be inserted into and secured in axial direction within these reception apertures. The axial securing in this case is likewise realized through a front-end staking of the planet pin to one of the two web metal sheets.
It is indeed possible to achieve a secure fixing of the bearing pin on the planet carrier by staking the bearing pin according to one of the two cited examples. However, this manner of fixing necessitates a more complex manufacturing method accompanied by a high cost factor.